CN102803704B - Distributing valve - Google Patents

Abstract

Distributing valve (2), be particularly useful for air compressing, the solenoid valve of the Fuelinjection nozzle of the internal-combustion engine of self ignition, there is valve member (3) and valve closure body (5), described valve member constructs valve seat surface (4), and described valve closure body becomes sealing seat with described valve seat surface (4) acting in conjunction.Described valve member (3) has guide section (26), and described valve closure body (5) is led on this guide section by guide openings (27).And described valve member (3) has at least one passage (32,33), described passage leads in the room (29) between described guide section (26) and described sealing seat.Such as can realize with the seat diameter (34) of 1.8mm at this sealing seat.

Description

distribution valve

technical field

The invention relates to a distribution valve, in particular a solenoid valve for a fuel injection valve and a fuel injection valve with such a distribution valve. The invention relates in particular to the field of injectors for fuel injection systems of air-compressed, self-igniting internal combustion engines.

Background technique

A fuel injector with a pressure-compensated control valve is known from DE 10 2006 021 741 A1. In the known injector, the injection valve element which releases or closes the injection opening is controlled by a control valve, wherein the control valve releases or closes the connection from the control chamber to the fuel return in that the closing element is provided In the seat or release the seat. In the case of this control valve, the hydraulic pressure is minimized by pressure compensation. As a result, the spring force is reduced with simultaneously smaller lift and larger cross-sectional area. Short switching times and favorable dynamics are thereby possible.

The fuel injector known from DE 10 2006 021 741 A1 has the disadvantage that the inclination of the armature due to the formed flat seat and the lack of centering effect can lead to looseness on the seat. Furthermore, the control valve is relatively sensitive to particles, since the bearing effect is limited. Furthermore, the seat is delimited only by the armature, wherein there is a very small seat length with two functional edges, which even has a negative effect on coatings or on the ingress of particles.

Contents of the invention

The distribution valve according to the invention with the features of claim 1 and the fuel injection valve according to the invention with the features of claim 12 have the advantage that the way of functioning is improved. The advantage is in particular that a robust dispensing valve can be created which is also suitable for high pressures.

Advantageous developments of the distribution valve specified in claim 1 and of the fuel injection valve specified in claim 12 are possible by means of the measures listed in the subclaims.

It is advantageous if the chamber of the valve part, into which the passage between the guide section and the sealing seat opens, is formed at least partially in the guide opening. Furthermore, it is advantageous here if a recess is provided on the valve part between the guide section and the valve seat surface, and the chamber of the valve part, into which the channel between the guide section and the sealing seat opens, at least substantially through the The groove is predetermined, wherein the inner wall of the guide opening delimits the chamber predetermined by the groove. A compact design of the at least substantially pressure-compensated distribution valve is thus possible.

It is also advantageous if the guide opening is designed as a guide bore, in particular as a through guide bore, and at least the guide section of the valve element is formed axially symmetrically with respect to the axis of the guide bore. Guidance between the valve part and the valve closing body is thus ensured such that a leak-tightness at the sealing seat is prevented by the inclined position of the valve closing body. Furthermore, it is advantageous here if a relatively large guide gap is predetermined between the guide section and the guide bore. As a result, the tensile load between the guide section and the other valve parts can be reduced. Through this relatively large guide gap, targeted leaking is possible.

However, it is also advantageous if a lateral sharpening is provided on the guide section, on which a leakage gap is provided between the guide section and the guide bore. Tensile loads between the guide section and other valve parts can also be reduced by means of this leakage gap.

The channel leading into the chamber between the guide section and the sealing seat is advantageously designed as a throttled channel. In particular, an outflow throttle can be implemented via this channel.

It is also advantageous if the valve closing body has a sealing edge facing the valve seat surface, the sealing seat is formed between the sealing edge and the valve seat surface and the seat diameter of the sealing seat and the valve part are predetermined by the sealing edge. The diameters of the guide sections are at least approximately the same size. As a result, very small seat diameters can be achieved, wherein sufficient high-pressure strength is achieved. Due to the small seat diameter, a reliable tightness of the closed sealing seat is ensured even at very high pressures.

Furthermore, it is advantageous here if the valve seat surface is designed as a conical valve seat surface and the opening angle of the conical valve seat surface is selected from a range of approximately 80° to approximately 120°. Furthermore, it is advantageous here if the sealing edge is formed on the conical end surface of the valve closing body and the opening angle of the conical end surface is greater than the opening angle of the conical valve seat surface. This achieves an advantageous centering of the valve closing body with respect to the valve seat surface of the valve part. Leakage at the sealing seat is thus prevented by the inclined position or the like. Furthermore, a seat limiter is installed in or on the valve element.

It is particularly advantageous if the seat diameter of the sealing seat is not greater than 2 mm, in particular approximately 1.8 mm. Relatively large leaks, which occur for example with a seat diameter of 2.5 mm, can thus be prevented and a high-pressure strength for very high pressures, in particular for pressures greater than 160 MPa (1600 bar), can be created.

Description of drawings

Preferred embodiments of the present invention are explained in detail in the following description with reference to the accompanying drawings. The accompanying drawings show:

FIG. 1 shows a distributing valve of a fuel injector in a simplified schematic sectional illustration according to an exemplary embodiment of the invention.

Detailed ways

FIG. 1 shows an exemplary embodiment of a fuel injector 1 with a distribution valve 2 in a schematic, schematic axial section. The fuel injection valve 1 can be used in particular as an injector of a fuel injection system for an air-compressed, self-igniting internal combustion engine. A preferred application of the fuel injection valve 1 is for a fuel injection system having a fuel distribution plate which conducts diesel fuel under high pressure to a plurality of fuel injection valves. However, the fuel injector 1 according to the invention and the distribution valve 2 according to the invention are also suitable for other applications.

The distribution valve 2 has a valve part 3 on which a valve seat surface 4 is formed. Furthermore, the distribution valve 2 has a valve closing body 5 which cooperates with the valve seat surface 4 to form a sealing seat. In this exemplary embodiment, the valve closing body 5 is part of the armature 6 . In this case, the valve closing body 5 is formed in one piece with the armature 6 . However, the valve closing body 5 can also be connected to the armature 6 . A solenoid coil 8 is arranged in the magnetic core 7 of the fuel injection valve 1 and is used to generate a magnetic field for actuating the valve closing body 5 of the armature 6 by means of the magnetic core 7 . As a result, the sealing seat formed between the valve closing body 5 and the valve seat surface 4 can be opened or closed. Here, the armature 6 is guided on a pressure pin 9 , which is supported on a support element 10 . Furthermore, a valve spring 11 arranged between the support element 10 and the armature 6 is provided in order to act upon the armature 6 against the magnetic force of the magnetic core 7 , which is controlled by the current flowing through the magnetic coil 8 . In this case, the force of the valve spring 11 influences the contact force with which the edge 12 of the valve closing body 5 acts on the valve seat surface 4 when the sealing seat is closed.

In this exemplary embodiment, valve part 3 is inserted into a further housing part 13 of fuel injector 1 . In this case, the valve part 3 is supported on a shoulder 14 of the housing part 13 . The valve part 3 has a bore 15 in which a control chamber 16 is delimited by a valve piston 17 . An inflow throttle 18 leads into the control chamber 16 , which connects the control chamber 16 with a high-pressure chamber 19 in the interior of the housing part 13 .

Distribution valve 2 has an axis 25 on which armature 6 and valve part 3 are aligned. In this case, the armature 6 is configured axisymmetrically with respect to the axis 25 . The valve part 3 is designed substantially axisymmetrically with respect to the axis 25 , and has a guide section 26 which is guided in a guide bore 27 of the armature 6 . In this case, the guide hole 27 is designed as a through-guide hole 27 . Furthermore, the pressure pin 9 extends into this guide bore 27 in order to guide the armature 6 on the pressure pin 9 . A recess 28 is provided on the valve part 3 between the guide section 26 and the valve seat surface 4 . A fuel chamber 29 is formed by this recess 28 , which is delimited by an inner wall 30 of the guide bore 27 of the armature 6 . The fuel chamber 29 is therefore formed between the guide section 26 and the valve seat surface 4 .

The valve part 3 has an axial blind bore 31 from which a channel 32 and a channel 33 branch off. Via a blind hole 31 and channels 32 , 33 , the control chamber 16 communicates with the fuel chamber 29 . In this case, the channels 32 , 33 are configured as throttled channels 32 , 33 . The two channels 32 , 33 open into the fuel chamber 29 between the guide section 26 and the sealing seat, which is formed on the edge 12 between the valve closing body 5 and the valve seat surface 4 . In this exemplary embodiment, the fuel chamber 29 is formed in the guide bore 27 .

In this exemplary embodiment, the edge 12 of the valve closing body 5 is designed as a sealing edge at which a sealing seat between the valve closing body 5 and the valve seat surface 4 is realized. The sealing edge 12 faces the valve seat surface 4 . In this case, the diameter 34 of the sealing edge 12 is at least approximately the same size as the diameter 35 of the guide section 26 . Pressure compensation is thereby achieved with respect to the fuel chamber 29 . Furthermore, the diameter 34 is very small so that the seat diameter of the seal seat is also very small. The diameter 34 and thus the seat diameter on the sealing edge 12 is, for example, not greater than 2 mm, in particular approximately 1.8 mm.

In this exemplary embodiment, the armature 6 has an end face 36 which faces the valve seat face 4 of the valve part 3 . The sealing edge 12 is formed between the end face 36 and the inner wall 30 of the guide bore 27 . The sealing edge 12 thus also lies on the end face 36 , but has the smallest diameter 34 . The conical seat surface 4 has, for example, an opening angle of 90°. As a result, an advantageous centering of the valve closing body 5 with its sealing edge 12 is achieved on the valve seat surface 4 . The opening angle of the conical end surface 36 of the valve closing body 5 is greater than the opening angle of the conical valve seat surface 4 , that is to say in the exemplary embodiment is selected to be greater than 90°.

The opening angle of the conical seat surface 4 is determined by the required centering and can lie in a range of less than 120°. It is especially advantageous if it lies in the range from approximately 80° to approximately 120°. The opening angle of the conical end surface 36 of the valve closing body 5 is then selected to be greater than the opening angle of the conical valve seat surface 4 .

The seat surface 4 is delimited by a step 37 . The maximum diameter 38 of the valve seat surface 4 to the seat delimitation is thereby predetermined. In this case, the seat delimitation can be attached to the valve part 3 via a step 37 or also in another way.

The guide section 26 is preferably relatively short along the axis 25 . This short section 26 serves essentially for centering during assembly. The armature 6 is guided by the pressure pin 9 . The pressure of the seat diameter is preferably taken up by the pressure pin 9 . Thus, it is supported by the support element 10 on the magnet set. In this case, the guide section 26 is not sealed against the high pressure in the fuel chamber 29 . This ensures that the valve part 3 is not stretched in the region of the recess 28 and in particular at the outlets of the channels 32 , 33 , and therefore no or only low tension occurs in the valve part 3 in this region. Here, tension relief can be provided. This is achieved, for example, by a relatively large guide gap between the guide section 26 and the guide bore 27 of the armature 6 . In addition or alternatively, a sharpening 39 is provided on one side of the guide section 26 , which forms a leakage gap between the guide section 26 and the inner wall 30 of the guide bore 27 . The pressure in the guide bore 27 between the guide section 26 and the pressure plug 9 can be adapted to the pressure in the fuel chamber 29 by means of a targeted leak.

However, an embodiment of the guide section 26 is also advantageous in which no sharpening 39 or the like is provided. The guide section 26 is thus configured axisymmetrically with respect to the axis 25 . A certain guidance is thereby also achieved in order to achieve a secure closing of the sealing seat between the sealing edge 12 and the valve seat surface 4 . In particular, tilting between the valve closing body 5 and the valve part 3 is prevented or at least reduced, so that self-centering of the sealing edge 12 on the conical valve seat surface 4 is supported.

The invention is not limited to the described embodiments.

Claims (15)

1. Dispensing valve (2) with valve part (3) and valve closing body (5), on which valve seat surface (4) is constructed, the valve closing body and the valve seat surface (4) Acting together as a sealing seat, the valve part (3) has a guide section (26) on which the valve closing body (5) is guided by means of a guide opening (27), and the valve part (3 ) has at least one channel (32, 33) which opens into the chamber (29) between the guide section (26) and the sealing seat, characterized in that the armature (6) (9) upper guide, the pressure plug is supported on the supporting element (10), and a leakage gap is formed between the guide section (26) and the guide opening (27), so that in the guide opening (27) The pressure between the guide section (26) and the pressure plug (9) is adapted to the pressure in the chamber (29). 2. Dispensing valve according to claim 1, characterized in that all the passages (32, 33) of the valve part (3) between the guide section (26) and the sealing seat lead into it. The chamber (29) is formed at least partially in the guide opening (27). 3. Distribution valve according to claim 1 or 2, characterized in that a groove ( 28), the chamber (29) into which the channel (32, 33) of the valve member (3) between the guide section (26) and the sealing seat opens at least substantially through the The groove ( 28 ) is predetermined, wherein an inner wall ( 30 ) of the guide opening ( 27 ) delimits a chamber ( 29 ) predetermined by the groove ( 28 ). 4. Distribution valve according to claim 1 or 2, characterized in that the guide opening (27) is configured as a guide hole (27), and at least the guide section (26) of the valve part (3) is opposite to The axis (25) of the guide hole (27) is formed axisymmetrically. 5. Distribution valve according to claim 1 or 2, characterized in that lateral sharpenings (39) are provided on the guide section (26). 6. Dispensing valve according to claim 1 or 2, characterized in that said channel (32, 33) leading into said chamber (29) between said guide section (26) and said sealing seat ) is configured as a throttling channel (32,33). 7. Dispensing valve according to claim 1 or 2, characterized in that the valve closing body (5) has a sealing edge (12) facing the valve seat surface (4), the sealing seat forming Between the sealing edge (12) and the valve seat surface (4) and the seat diameter (34) of the sealing seat predetermined by the sealing edge (12) and the valve part (3) The diameters (35) of the guide sections (26) are approximately the same size. 8. Distribution valve according to claim 7, characterized in that the valve seat surface (4) is configured as a conical valve seat surface (4) and the opening angle of the conical valve seat surface (4) is from 80 ° to 120° range selection. 9. Distribution valve according to claim 8, characterized in that the sealing edge (12) is formed on a conical end face (36) of the valve closing body (5) and the conical end face (36) The opening angle is greater than the opening angle of the conical valve seat surface (4). 10. Dispensing valve according to claim 7, characterized in that said sealing seat has a seat diameter (34) not greater than 2 mm. 11. Distribution valve according to claim 1 or 2, characterized in that the distribution valve (2) is a solenoid valve for a fuel injection valve of an air-compressed, self-igniting internal combustion engine. 12. The dispensing valve according to claim 4, characterized in that the guide opening (27) is designed as a through guide bore (27). 13. Dispensing valve according to claim 10, characterized in that said sealing seat has a seat diameter (34) of approximately 1.8 mm. 14. Fuel injector (1) having a distribution valve (2) according to one of claims 1 to 10. 15. The fuel injection valve according to claim 14, characterized in that the fuel injection valve (1) is used as an injector of a fuel injection system of an air-compressed, self-igniting internal combustion engine.